Liquid medical waste is flowed into medical waste containers. The liquid medical waste is deposited under the influence of a suction, which directs the liquid through a conduit. The waste is usually an aqueous fluid mixture of saline, blood, urine, and/or other bodily fluids. Regulations require that the liquid be converted to a solidified form prior to transport in order to minimize the possibility of hazardous waste being spilled.
While solidifiers have attempted to reach firm solidification, where no fluids will spill when the container is turned on its side, a problem with “gel block” has persisted. Development of “gel block” prohibits firm solidification. “Gel block” occurs when the inflowing aqueous mixture becomes solidified and sections off portions of the fluid so that it can not reach available solidifier. When gel block occurs, the aqueous fluid does not firmly and completely solidify and spillage during transport is problematic.
Previously, the problem of “gel block” has been addressed in a variety of ways. Various solidifiers with different densities have been combined so that the solidifier will migrate to specific levels or zones of the fluid. However, weighted solidifiers take some time to reach their separated levels, and the use of swifter solidifiers with this system still presents problems with “gel block.” Additionally, the speed with which the fluid is introduced and the timing of the release of weighted solidifier is extremely important if the weighted solidifier is to inhibit “gel block.”
Superabsorbants are known in the art as water-swellable, water-insoluble, organic or inorganic material capable of absorbing at least about 100 times its weight and up to about 300 times its weight in an aqueous solution. Superabsorbent polymers are cross-linked, neutralized polymers which are capable of absorbing large amounts of aqueous liquids and body fluids, such as urine or blood, with swelling and the formation of hydrogels, and of retaining them under a certain pressure in accordance with the general definition of superabsorbent. The main use for internally cross-linked superabsorbent polymers has been in sanitary articles.
The trend in sanitary articles, for comfort and sanitation reasons, has been to make them smaller and reduce their size. To do this, much of the fluff fiber in these articles has been removed and more superabsorbent polymer has been added. With less structure provided, more superabsorbent polymer is needed in sanitary articles along with a higher gel strength. However, increasing gel strength in cross-linked superabsorbent polymers often results in less polymer swellability, permeability and retention capacity. U.S. Pat. No. 7,291,674 to Kang addresses surface cross-linking superabsorbent polymers in order to retain liquid retention, permeability, and gel bed strength when superabsorbent polymer is increased in percent by weight based on the absorbent structure.
Additionally, it is known in the art to add non-polymeric particles to internally cross-linked superabsorbent polymers in order to increase the swellability of the superabsorbent polymers. In fiber optic applications, the cables are coated with a mixture of superabsorbent polymer and non-polymeric silica particles. If the cable covering is breached and fluid seeps inside, the mixture leads to “gel block” and acts as a gelling agent where the superabsorbent polymers have enhanced swellability so that they water block. In such an application gel block is desired and the particle mixture is designed to achieve gel block as a desired end result.
While the advancements of absorbents, as discussed above, have increased the swellability and strength of superabsorbent polymers, they do not assist with use in the solidification of liquid medical waste due to persistent problems with “gel block.”